Production of lubricating oils



2, 1940- c. cLA ET AL ,206,391

PRODUCTION OF LUBRIQATING OILS Filed Sept. 24, 1937' Patented July 2,1940 UNITED STATES PATENT OFFICE l V z,2oc,s91 I cst cl'fi llflfiffffi11 m Goethel, Duisburg-Hambom, signors to Rnhrchemie Germany, as- IAktiengesellsc Oberhausen-Holten, Germany Application September 24,1937, Serial him-165,566

' In Germany October 1, 1936 4 Claims; (Cl. 196-78) Our inventionrelates to lubricating oils and more particularly to 'an improved methodof producing same.

It is an object of our invention to produce lu- 5 bricating oils bypolymerizing olefines by means of a polymerizing catalyst.

It is another object of our invention to artificially producelubricating oils ofa predetermined viscosity.

It is a further object of.our invention to improve the methods ofproducing lubricating oils disclosed in the copending applications forU. S. Letters Patents, Serial No, 115,950 filed December 15, 1936, byGeisenand Goethel and :Serial No. 115,951, filed December 15, 1936, by I-Ieinrich Tramm.

It is known to produce lubricating oils by polymerizingliquid crackingproducts with the aid of polymerizing catalysts or condensing agentssuch as metal halides, for instance aluminium,

chloride. Oils of a higher orlower viscosity are obtained thereby independency on the kind of the starting materials and on the reactioncon'- ditions. It is further known that the physical properties of thelubricating oil obtained depend on the specific starting materials usedfor the production of the cracking benzine which treated to condense orpolymerize to lubricating oils. It has been suggested for instance, inorder to obtain lubricating oils of particularly low solidifying points,to start the production of the cracking benzine from a hydrocarbonmixture consisting of hard and soft paraifins.

It is known that the viscosity of lubricating oils produced by treatingolefines with a polymerizing catalyst, such as a metal halide, may beinfluenced by the quantity of the polymerizing catalyst employed, thetemperature prevailing during the polymerization and the duration of theolymerization.

- If'difierent'oleflnes or mixtures of oleflnes or, for instance,different cracking benzines are subjected to polymerization, differentabsolute values of the three factors must of course be chosen. We havefurthermore found that the polymerization of the cracking products tolubricating oils may be carried through within substantially shorterperiods of time, if in the first of several subsequent conversiontreatments of the cracking benzine a quantity of polymerizationcatalyst, preferably aluminium chloride, is used. which is about'3 to 6times as large as the hitherto used quantity and thus ranges betweenabout 3 and 6 per cent aluminium chloride, calculated on the hydrocarbonmixture treated. If the first bhtchof cracking benzine-to be convertedis treated for instance with about 5% aluminium chloride instead of only1%, the polymerization of the cracking products to lubricating oils willbe complete already after about 12 hours, if within the 5 whole time ofpolymerization the polymerization temperature is caused to graduallyrise from about 20 C. to about -80 C. The contact layer, which comprisesthe aluminium chloride sludge formed, after having been separated from10 the upper layer, which latter contains the polymerized products, andafter-having been revived by the addition-of a small quantity, amountingto about 0.5-2%, calculated on the quantity of the cracking benzineused, of fresh 'polymeriza- 1 tion catalyst serves for converting a newbatch of cracking benzines. Again the polymerization of-the crackingbenzines to lubricating oils will be complete within the course of 12hours, if the temperature is raised in the same mannerfrom 20 about 20to 60-80 C. The contact layer obtained in the conversion of the firstbatch may be frequently reused in this manner, after having been revivedeach time.

We obtain particularly favorable results when 25 using a crackingbenzine produced from socalled primary synthetic benzine, i. e., abenzine as obtained by catalytic hydrogenation of carbon monoxide withhydrogen at low pressure, such as atmospheric or reduced pressure or anypres- 30 sure not substantially above 2 atmospheres, according to thewell known method of Fischer and Tropsch. We cracked for instancesynthetic parafflnic hydrocarbons, boiling above 0., such as obtainedaccording to the method of 35 Fischer and Tropsch, so as to form acracking benzine with a specific weight, at 20 C., of 0.700

to 0.718, 25-50% of which boiled below 100- C., while about 90-100%distilled over at tempera-' tures up to C. with this cracking benzine 40the conversion could subsequently be carried out up to 60 times, the oldcontact. layer which was not yet exhausted, being always reused. By thefrequent re-use of the contact layer or sludge the consumption or thealuminium chloride is 45 hardly increased in spite of the increaseinthequantity of this catalyst employed at the start. By the re-use of thereactivated contact layer the further advanta e is obtained that eachconversion of cracking products is carried out with a polymerizingcatalyst of the same activity, so that a polymerlmtion product ofuniform properties may be obtained in continuous technicalo'peration. yY We have further found that the viscosity-of the lubricating oilsformed may be influenced by that quantity of polymerization catalystwhich is added afresh to the contact layer, which comprises thealuminium chloride sludge. If for instance in the manner of operationdescribed above 0.5% fresh aluminium chloride, instead of 1.3%, areadded .to one of the subsequent batches of cracking benzine and thepolymerization is conducted with the same increase of temperature andduring the same time of polymerization, the yield of lubricating oildoes not drop, but an oil is obtained, the viscosity of which hasdropped nearly to one half of the viscosity-oi the lubricating oilbefore obtained. The viscosity of the lubricating oil formed may thus beinfluenced by varying the quantity of fresh polymerizing agent: asmaller quantity of polymerizing catalyst causes a decreased viscosity,while with a larger quantity of polymerizing catalysts lubricating oilsof higher viscosity are produced. In the production of lubricating oilsof lower viscosity we prefer, under certain circumstances, to raise thetemperature during the period of polymerization still higher, forinstance from 20 up to -100 C. In order to obtain higher viscosities, wefound it furthermore advisable to extend the duration of thepolymerization up to for instance 16-18 hours, while keeping the other,conditions constant. p

The drawing accompanying this specification is a flow sheet illustratingin a diagrammatic manner an embodiment of our invention.

Referring to the drawing, A is a reaction vessel, while L is a coverwhich may be screwed on this vessel to close it. In the vessel A isarranged the coil 13 which serves" for the passage of cooling means aswell as heating means. The cooling means enters the coil at C and leavesit at E. The steam, which may be employed as heating means, enters thecoil at F, while the condensed steam is withdrawn at D. Shaft H, theinlet I for the benzine to be polymerized, the suction pipe K for thewithdrawal of the poly merized hydrocarbons and the tube G for theintroduction of the catalyst pass through the cover L. In operation thereaction vessel A is charged with the benzine hydrocarbons and thecatalyst, polymerization being carried through by controlling thetemperature by means of heating or cooling means passing through coil13. After polymerization is completed and the aluminium chloride sludgehas settled down, the polymerized constituents are withdrawn throughpipe K by suction. Pipe K may simultaneously be em.- ployed as safetytube when the pressure changes.

The invention may be explained further by the following examples, all ofwhich start from cracking benzines produced by cracking such benzineswhich were obtained by hydrogenating carbon monoxide according to themethod of Fischer and Tropsch. Other hydrocarbon mixtures containingoleflnes', for instance benzines rich in oleflnes, as recovered by acatalytic dehydrogenation, may, however, be polymerized in the same way,i. e., the viscosity of the lubricants produced may be controlled by thesame meas- In carrying out the present invention, all the details ofoperation may be utilized which were disclosed in the copendingapplications Serial Nos. 115,950 and 115,951 mentioned above andmore'particularly those details which have regard to thereactiv'ationandthe frequent re-use of the polymerization catalyst or condensingagent and those having regard to the control of the temperatureprevailing in the course of a single polymerization as such, andwhichmay gradually or stepwise be increased, and in relation to thepreceding or the subsequent polymerization treatments. Accordingly thetemperature may range between about 20 and C.; the period ofpolymerization for each charge treated at practically the'sametemperature may range between about 12 and 20 hours. I

The first examples show how the viscosity of the oils produced dependson the quantity of the polymerization catalyst and on the temperatureprevailing during polymerization. In each of the examples 1-5, fivesingle experiments are compiled which were carried through successivelyunder the same conditions of reaction. The duration of thepolymerization amounted to 12 hours in each case. The quantities ofpolywhole time of polymerization amounting to 12' hours the content ofthe vessel is thoroughly stirred, while the temperature is increased inthe manner described in the following examples. The increase of thetemperature in the course of the period of polymerization differs ineach example. After a lapse of 12 hours, during which the polymerizationis carried out, the vessel is allowed to cool down to room temperature;thereby the contact layer settles in the form of an oily layer. Fromthis contact layer there is then separated the upper layer whichcontains the lubricating .011 formed and those parts of the benzinewhich have not been converted into lubricating oil. The separated upperlayer is treated with acid and lye and subsequently washed with water,and thereupon dried. From the dried product of reaction thenot-converted benzine is distilled off up to 0.; this distil-v late isdesignated in the following tables as re- 1;

sidual benzine. The remainder of the distill'azine, middleoil andlubricating oil is scheduled in the tables in per cents by weightcalculated on the quantity of the starting cracking benzine. In order tocharacterise the physical qualities of the lubricating oils obtained,the vi'scosities in degrees Engler (E.) at 50 C. and the densities at 20C. are mentioned also.

Example 1 5 tests were carried through, in each of which 0.5% by weightaluminium chloride, calculated on the quantity of benzine used, wereadded to the contact oil layer before thebeginning of thepolymerization. The temperature of polymerization was caused to risestepwise in the course of Experiment-No.

each conversion, the polymerization being car ried through two hours at20, 4 hours at 5 0 .and 6 hours at 70 C. Table 1 shows the detailed dataof the experiments and the results.

tion or the polymerization was the same-as Examples 1 and 2. In bothExamples (3 and 4) polymerization was carried through: rour hours at 20and eight hours at 50. while the quantity Tum: 1

300 8,055 0,000 5,455 8,000 055 9,000 8,455 -s,9s0 15,150 000 15,00015,000 .000 --15,000 15 75 7.5 75 75 350 14,050 15,100 14,550 15,15022.5 22.5 33.0 s2 32 21.4 13.2 10.0 14 20 51 50.0 54 48 4s 0.858 0.8530.852 0.852 0.058 8.55 a 04 s. 00 1. s. 15

Example 2 In the 5 experiments next following 1% by weight aluminiumchloride, calculated on the quantity of cracking benzine employed, wasadded before the beginning of the polymerization to the mixture to betreated. Polymerization of added polymerization catalyst difiered in thetwo examples. With an average quantity of polymerization catalystof 1%by weight, calculated on the starting quantityof cracking beuzine,lubricating oils were obtained which showed a viscosity of 50 C. or15-18 E. Table 3 shows was carried through two hours at 20, 4 hours atthe detailed data of the experiments and results.

- TABLE 3 Experiment N 1 2 3 4 5 Charge:

Quantity ol'contsct oil in grams- Before conversio 17, 820 18, 350 18,950 19, 150 19, 380 Alter conversio 18. 350 18,950 19, 150 19, 38019,980 Benzine employed in grams 16,000 15,000 000 15, 000 15,000Addition of trash MCI; in --v----- 180 150 150 150 150 Products 0!reaction obtained 11 r layer) in grams 14, 830 14, 550 14, 950 14, 92014, 550 Content of the upper layer in r ual benzlneflfl. 41. 4 42. 8 33.7 39. 9 3. 8' Middle nil 10.1 8.9 14. 55 7.0 6.8 Lubrirntin oil 45. 045. 0 60. 4 5i. 6 55. 3 Density 0! the ubricating oii at 20 C--. 0. 8620. 868 Viscosity'oi the lubricating oil at 50 0--.... ....-E.- 18.0 15.015.4 17. 5 18 50 and: 6 hours at 70. As compared with Ex- Example 4ample 1, lubricating oils of higher viscosity were obtained by the useof a larger quantity or aluminium chloride, while the duration and thetemperatures of polymerization were the same. Table 2 shows the detaileddata of the experiments of 1%, were added to the single charges. By theand the results. increased quantity of polymerization catalyst oilsTaste 2 Experiment Nn 1 2 3 4 5 Charge: 7

Quantity of contact oil in grams- Before conversion 10, 150 10, 50011,100 10,800 11, 180 Alter conversion 10, 500 11, 10, 800 11, 180 11,280 Benzine employed in grams 15,000 15,000 15,1110 ,000 15, 000Addition oi fresh A1015 in ams 150 150 150 150 Products 0! reactionobtained upper layer grams 14, 800 14, 550 15, 450 14, 770 15, 050Content of the upper layer in residual benzine .percent.- 42. 5 7. 3 36.6 35. 5 32 Middle oil (in 11. 0 6. 4 20. 0 10. 1 17. 2 Lubricating oil.do 44. 6 40. 2 43. 8 44.8 50 Density oi the lubricating oil at 20 C 0.851 0. 851 0. 852 0. 853 0. 852 Viscosity oi the lubricating oil at 50 CE-. 12. 5 12. 15 14. 2 12.12 12. 4

Example 3 with a higher viscosity were obtained, viz. with In Examples 3and 4 lower temperatures of polymerization were employed, while theduraa viscosity of 20-22 E. at 50 C. Table 4 shows the results.

Tana: 4

Experiment No 1 2 3 4 5 shall-age: t't r t t ilingramsnan 1 y 0 con so 0Before conversion 13, 810 15, 210 14, 910 15, 510 15, 9Q) Afterconversion.... 15, 210 14, 910 15, 510 15, 990 16, 890 Benziue employedin 15, 000 15,000 15,000 15,000 15,000 Addition of fresh aw in grams.--200 200 200 200 200 Products oi reaction obtained up layer) in grams 13,800 15, 500 14, 000 14, 720 14, 300 Content of the upper layer in resual benzine percent 35. l 39. 6 34 37. 3 41. iddle nil 0...... 7. 6 10.6 ll 7. 4 3. Lubrica 011 d0.-.- 47. 0 52. l 51. 0 53. 0 49 Density ofthe ubricating oil at 11 C..- Viscosity of the lubricating oil at50C.-." 20. 3

Example 5 Five experiments were carried out again with a 12 hoursdurationof polymerization, the temperature of polymerization beingmaintained two hours at 20, four hours at 50 and the last six hours at70. The 'quantityof aluminium chloride added to each charge amounted to1.3%.

These experiments show that by simultaneously increasing the temperatureand the quantity of the polymerization catalyst, the viscosity of thelubricating oils obtained is increased to a higher extent than if onlythe temperature or only the quantity of polymerization catalyst isincreased, so that lubricating oils were obtained with a viscosity of15-20 E. at 50 C. Table 5 shows the data of experiments and the results.

. Example 7 200 grams fresh aluminium chloride and 15,000 grams crackingbenzine were added to a quantity of contact oil amounting to 9,520 gramsin an autoclave provided with an agitator. For 60 hours the temperaturein the autoclave was maintained at 20 0., while the reaction mixture wasvigorously stirred. After the reaction had been completed, an upperlayer containing the products of reaction andamounting to 14,650 gramswas obtained, while 10,050 grams of contact oil remained in the vesseland were employed for further conversions. The upper layer was treatedin the manner described above for the recovery of lubricating oil; wethereby obtained 7280 grams TABLE 5 Experiment No I 1 2 3 4 5 Chase: ati t t '1' gram uan yo con ac 01 111 s- Before conversion 7, 000 7, 7508, 550 7, 250 7, 050 After conversion. 7, 750 8, 550 7, 250 7, 650 8,060 Benzine employed in grams 15, 000 15, 000. 15, 15, 000 15, 000Addition of fresh AlCh in grams 200 200 A00 00 200 Products of reactionobtained (upper layer) in grams 14, 450 14, 400 16, 500 14, 800 13, 900Content of the upper layer in residual benzine, .pereenL. 32. 0 31. 136. 0 24. 6 24. 0 Middle oil ..do 11. 2 11. 0 12. 3 13. 4 14. 6Lubricating o do 52. 8 63. 6 62. 0 69. 8 54. 1 Density of thelubricating oil at 20 C 0. 858 0. 857 0. 857 0. 856 0. 856 Viscosity oithe lubricating oil at 50 0 10.. 20. 86 18 15.8 15. 5 17. 3 I

Example 6 of a lubricating oil or a viscosity of 2'7.2 E. at

The following experiments illustrate the influence of the duration ofthe polymerization on the viscosity of the lubricating oils obtained. Toa contact oil layer recovered in preceding conversions and amounting to6650 grams there-are aded 150 grams aluminium chloride and 15,000 gramscracking benzine in an autoclave provided with an agitator. Thetemperature in the autoclave is maintained at 20 C. for the first fourhours and then increased to and maintained eight hours at 50 C. Theproducts of reaction are then allowed to settle and a sample is takenfrom the upper layer. The sample was distilled to remove the residualbenzine and subsequently distilled in.

vacuo to remove the insufflciently condensed middle oils. There remainedover, with a yield of 49%, a lubricating oil showing a viscosity of 16.8E. at 50 C. The polymerization of the batch was continued another fourhours at the same temperature of 50 C., whereupon another sample wastaken and examined in the same manner. The product of reaction nowproved to contain 49.4% of a lubricating oil, which had a liscosityofl9.7 E. at 50 C. A further extension of the duration of polymerizationfor four hours caused the content of the reaction product in lubricatingoil to rise to 50.4%, and the lubricating oil thus obtained had aviscosity of 20.8 E.

The samples taken from the upper layer were treated in the mannerdescribed above by washing with acid, lye and water and subsequentlydrying.

obtained, while thinner oils of lower viscosities.

were obtained, it higher temperatures and shorter periods ofpohrmerization were employed.

Example 8 To 8650 grams contact oil were added, in an autoclave providedwith an agitator, 150-grams fresh aluminium chloride and 15,000 gramscracking benzine. After 481 hours, during which the In the sameautoclave 15,000 grams cracking benzine were mixed and treated at 50 C.with 1% by weight fresh aluminium chloride (of 11101:) and a quantity-of11,250 grams contact 011; after the lapse of four hours thepolymerization was terminated. An upper layer amounting to 15,290 gramswas obtained, from which 7040 grams lubricating oils having a viscosityof 155 E. at'50 C. could be recovered.

The term gradually raising the temperature, as used in the specificationand the claims, is intended to include also a stepwise increase.

Various changes may be made in the details disclosed in the foregoingspecification without departing from the'invention or sacrificing theadvantages thereof.

1. In the production of lubricating oil by polymerizing benzinehydrocarbons in a series of suc cessive polymerization operationscarried out in the presence of aluminium chloride as polymerizationcatalyst at a temperature ranging, in dependency on the viscositydesired of the lubricating oil to be produced, between 20 and C.. duringa period of time ranging in each of said operations,'in dependency onthe viscosity desired of the lubricating oil to be produced, between-:5;

12 and 20 hours, wherein in' the first of said operations a portion orsaid benzinehyd'rocarbom is treated with 3 to 6 per cent aluminiumchloride, while in eachof the following operations another portion ofsaid benzine hydrocarbons is treated with the lower layer comprising thealuminium chloride sludge formed in a preceding operation, the step ofadding to said lower layer, when acting with it on a fresh portion ofsaid benzine hydrocarbons, a quantity of fresh aluminium chlorideamounting to approximately 0.5 per cent, calculated on the benzinetreated,

for the production of lubricating oil of low vis-' cosity, toapproximately 1 per cent for the production of lubricating oil of meanviscosity and to approximately 1.3 per cent for the production oflubricating oil of high viscosity, the temperature being raised in eachoperation while the polymerization proceeds.

2. The method of claim 1, when applied to the of the aliphatic series.

3. The method of claim 1, when applied to the production of lubricatingoil from synthetic benzine as obtained by hydrogenation of carbonmonoxide with hydrogen at an elevated temperature not exceeding about250 C. and under a zine hydrocarbons.

CARL CLAR. HERBERT GOETHEL.

production of lubricating oil' from hydrocarbon mixtures containingunsaturated hydrocarbons

